It's not a simple serialization issue, but related to the initial computations when a saved image is reloaded at the start of a session, so the implication is less general than you imply.
If you move the saved image to another file, say "savedImage", then: > load("savedImage") > library(urca) > showMethods("summary") Function: summary (package base) object="ANY" object="ca.jo" object="ca.po" object="cajo.test" object="ur.df" object="ur.ers" object="ur.kpss" object="ur.pp" object="ur.sp" object="ur.za" and summary(lc.df) then works as expected. So the workaround, other than inserting all the import(methods), etc. you can think of, seems to be to save/load explicitly. Seth Falcon wrote: > John Chambers <[EMAIL PROTECTED]> writes: > > >> I haven't had a chance to verify these exact examples, but the likely >> explanation is that loading the workspace does not cache the saved >> methods. Assuming this is indeed what's happening, the workaround is to >> cache them "manually" by the call: >> >> cacheMetaData(.GlobalEnv) >> >> (after attaching the relevant library) >> >> It would be nice to have the same effect occur automatically, but there >> may be issues since the needed class definitions may not be available >> when the saved workspace is reloaded. >> >> A natural question to ask is whether there is some practical motivation >> for this exercise. >> > > The main use case is that since serialization of objects is such an > R-ish thing to do, you really want to have deserialized S4 instances > "work" properly when loaded. > > I admit that it is also useful to be able to load an arbitrary object > and inspect it even if it will be "broken" (without this, it would be > very hard to write any sort of automated class update code). It would > seem that this behavior could be achieved in a force=TRUE mode and > that otherwise, it would be an error to deserialize an S4 instance > when the class def is not available. > > + seth > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel